Monoazo dye and process of making same.



THILO KROEBER,

SOCIETY or enemas. INDUSTRY IN OF BASEL, SWITZERLAND, ASSIGNOR TO THE FIRM OF BASLE, OF BASEL, SWITZERLAND.

MONOAZO DYE AND PROCESS F MAKING SAME.

Specification of Letters Patent.

Patented Feb. 19 1907.

Application filed December 6,1906. Serial No. 346,488. lSpeeimens.)

To It 107110711 777 may 1. 07).!3/3771: Be it known that I, TuILo linonnnn, chemist and doctor of philosophy, a subject of the Duke of SaxcAlte11burg, and a resident of Basel, Switzerland, have invented new and useful Improvements in the Manufacture of Monoazo Dyestuils, of which the following is a'clcar and complete specification.

According to the present invention the nitroamido-alpha-naphtholsulfonic acid which can be obtained by reducing naphthol yellow S (OH:NO :NO,:SO H=1:2:4:6 01' 7) in neutral or alkaline solution with iron or alkali sulfid is diazotized and combined with azo components to produce monoazo dyestu'l'l's which are valuable both in direct dyeing and for development by subsequentchroming.

The manufacture of the new nitroamidoalpha-naphtholsulfonic acid may be carried out, for example, as follows: Three hundred andfifty kilos of sodium dinitronaphtholsulfonate (naphthol yellow 8) are dissolved in about two thousand liters of water, and seven hundred kilos of iron-powder are added. While energetically stirring, the solution is heated at about from to 7 0 centigrade during about six hours-that is to say, the naphthol yellow has disappeared. Now the mixture, which shows a bluish-red coloration, is filtered, and the filtrate after being cooled down at ordinary temperature is acidified by means of hydrochloric acid until to a strong acid reaction on Congo paper. The

nitroamido-naphtholsulfonic acid is precipitated as a yellowish crystalline mass, which is freed from mother-liquor by suction. The new nitroamido-naphtholsulfonic acid corresponds probably to the 4-nitro-2-amido-L naphthol-6 or 7-sulfonic acid. tion may also he proceeded in alkaline solution with alkali sulfid or the like in the wellknown manner.

The manufacture of the new dyestufl's from this nitroamido-alpha-na )htholsul'fonic acid may be illustrated by the cllowing examples:

Example and seven kilos of sodium nitrite, whercu on the, diazo compound separates as yelow until The reduc I: 28.5 kilos of nitroamido-alphanaphtholsulfonic acid obtained by reducing.

crystals. The diazo compound thus obtained is introduced into an aqueous solution of seventeen kilos of sod um beta-naphthol mixed with thirty-five kilos of sodium carbo nate. The mass is stirred for some hours at the ordinary temperature, then heated to 50 centigrade and allowed to cool, whereupon the dyestuil' separates as green crystals having a metallic luster. It dyes wool in an acidbath directly black shades. By subse-' quent-ly treating the dyeings with chromium salts a deep brownish black is obtained.

Example II: The diazo mass obtained from 28.5 kilos of nitroamido-alpha-naphtholsulfonic acid according to Example I is combined with twenty-six kilos of sodium 1 :5-naphtholsulfonate in a solution made al kaline with sodium carbonate. The combination begins immediately. After stirring for several hours the separated dyestuff without preliminary heating is directly filtered, pressed, and dried. It forms a bronze-powder easily soluble in water to a violet-blue solution and dyes wool in an acid-bath beautiful blue-black shades, which pass to a deep fast black when subsequently chromed.

Example III: The aforesaid quantity of.

nitrodiazo alpha naptholsuifonic acid is combined with 14.5 kilos of 1:5-dioxynapthalene (oxynaphthol 1:5) in a solution made alkaline with sodium carbonate. A dyestuil is obtained which dissolves in hot water to ablue-black solution, passing to yellow brown on addition of acid. It dyes wool directly beautiful blue shades, which when subsequently chromed pass to extremely fastblack shades.

The corresponding dyestuif from 1 :6-dioxynapthalene dyes wool in an acid-bath violet-black shades, which pass toward brown when subsequently chromed.

In analogous manner dyestuffs may be made by any other azo-coloring-matter comonent.

What I claim is,

1. The process for the manufacture of monoazo dyestuffs, which consists in preparing a nitroamido alpha naphtholsulfonic acid by reduction of naphthol yellow S, diazot-izing the so obtained nitroamidoalpha naphtholsulfonic acid and combining the resulting nitrodiazoalpha-naphtholcomponent, as described.

2. The process for the manufacture of monoazo dyestufis, which consists in diazotizing the nitroamido alpha naphtholsulfonic acid obtainable by reduction of the naphthol yellow S and combining the resulting nitrodiazo alpha .naphth olsulfonic acid with a naphtholic compound. as described:

3. The process for the manufacture of a monoazo dyestufi, which consists in diam.-

tizing the nitroamido alpha-naphtholsull fonic acid obtainable by reduction of the naphthol yellow S and combining-the resulting nitrod iazo alpha naphtho'lsulfonic acid with beta-naphthol, as described.

4. An improvement in the manufacture of monoazo dyestuffs, which consists in preparing a nitro amido alpha naphtholsulfonic acid by reducing naphthol yellow S as above 'described.

5. As new products the monoazo dyestuffs derived from the diazo derivative of the nitroamido a1pha-naphtholsulfonic acid obtainable by reduction of naphthol yellow S, which dyestuffs dissolve in "water with acid with violet-blue to blue colorations and which dye unmordanted wool in blue-black tints, which tints become on treatment with chromium compounds deep black.

6. As a new product, the monoazo dyestufi derived from nitrodiazo alpha naphtholsulfonic acid obtainable by reduction of naphthol yellow S and from beta-n'aphthol, which coloring-matter yields a bluish-black aqueous solution turning to violet on addition of ammonia liquor, dissolves in concentrated sulfuric acid withviolet-blue colora tion and dyes unmordanted wool in blueblack shades, which shades. become deep brownish black on treatment with chromium compounds.

In witness whereof I have hereunto signed my name, this 17th day of November, 1906, in the presence of two subscribing witnesses.

I THILO KROEBER. Witnesses:

GEO. GIFFoRo, AMAND RITTER. 

